(P40) CHANGES TO NEISSERIA GONORRHOEAE MULTI-ANTIGEN SEQUENCE TYPES FOUND IN CANADA BEFORE AND AFTER THE CORONAVIRUS DISEASE (COVID-19) PANDEMIC.

Background:
Neisseria gonorrhoeae is the causative agent of gonorrhea. To monitor for trends in and emergence of antimicrobial resistance (AMR), the Gonococcal Antimicrobial Surveillance Program (GASP–Canada) was established. N. gonorrhoeae MultiAntigen Sequence Types (NG-MAST) is a genotyping system that uses the porinB (porB) and transferrin-binding proteinB (tbpB) sequences to assign sequence types (ST) to gonococcal strains. Strains sharing identical STs are highly related and frequently have similar AMR profiles. The COVID-19 pandemic led to a drastic decline in the numbers of several prevalent NG-MAST STs in Canada, accompanied by the detection of STs previously unseen in the country.

Methods:
N. gonorrhoeae cultures were submitted to the National Microbiology Laboratory in Winnipeg, Canada by provincial and territorial public health laboratories as part of GASP-Canada. MICs for seven antimicrobials were determined/predicted for the cultures by agar dilution or whole genome sequencing (WGS). NG-MAST STs were determined using conventional PCR or WGS.

Results:
In 2019, the two most common STs in Canada were ST-14994 (14.1%, n=413/2921) and ST-12302 (11.8%, n=345/2921). By 2022, the prevalence of these STs decreased to 1.6% (n=46/2544) and 0.7% (n=17/2544), respectively. The two most common STs in 2022 were ST-17972 (13.3%, n=338/2544) and ST-19875 (8.8%, n=320/2544). In Canada, ST-17972 was first detected in 2019, whereas ST-19875 first appeared in 2020. ST-12302 is strongly associated with azithromycin resistance (MIC ≥2mg/L) with upwards of 80% of strains resistant.  While over the course of the COVID-19 pandemic the level of AZI-R has not changed, the distribution has shifted from primarily ST-12302 to a wider array of STs.

Conclusion:
The COVID-19 pandemic altered NG-MAST ST prevalence within Canada. The overall AZI-R level has remained the same, though it is no longer as strongly associated with a single genotype. Continued surveillance of N. gonorrhoeae AMR will help monitor the changing NG-MAST and AMR dynamics.